Add quotation to children's input options if required (#42)

Author: andreas-gruenwald

src/Parallelization.php

@@ -541,14 +541,35 @@ private function serializeInputOptions(InputInterface $input, array $blackListPa
                 $optionString .= ' --' . $name;
             } elseif ($option->isArray()) {
                 foreach ($value as $arrayValue) {
-                    $optionString .= ' --'.$name.'='.$arrayValue;
+                    $optionString .= ' --'.$name.'='.$this->quoteOptionValue($arrayValue);
                 }
             } else {
-                $optionString .= ' --'.$name.'='.$value;
+                $optionString .= ' --'.$name.'='.$this->quoteOptionValue($value);
             }
 
             $preparedOptionList[] = $optionString;
         }
         return $preparedOptionList;
     }
+
+    /**
+     * Ensure that an option value is quoted correctly, before it is passed to a child process.
+     * @param mixed $value the input option value, which is typically a string but can be of any other primitive type.
+     * @return mixed the replaced and quoted value, if $value contained a character that required quoting.
+     */
+    protected function quoteOptionValue($value) {
+
+        if($this->isValueRequiresQuoting($value)) {
+            return sprintf('"%s"', str_replace('"', '\"', $value));
+        } else {
+            return $value;
+        }
+    }
+
+    /**
+     * Validate whether a command option requires quoting or not, depending on its content.
+     */
+    protected function isValueRequiresQuoting($value) : bool {
+        return 0 < preg_match('/[\s \\\\ \' " & | < > = ! @]/x', $value);
+    }
 }